Dtc P0038 [Lf] - Mazda 3 Workshop Manual

Mazda 3 Workshop Manual – Engine + Wiring Diagrams + Diagnostic Trouble Codes
• Inspect for continuity between rear HO2S
terminal D (wiring harness-side) and body
ground.
• Is there continuity?
INSPECT HREAR HO2S HEATER CONTROL
CIRCUIT FOR OPEN CIRCUIT
• Inspect for continuity between rear HO2S
8
terminal D (wiring harness-side) and PCM
terminal 2C.
• Is there continuity?
VERIFY TROUBLESHOOTING OF DTC P0037
COMPLETED
• Make sure to reconnect all disconnected
connectors.
• Clear the DTC from the PCM memory using
9
the WDS or equivalent.
• Perform the HO2S heater, HO2S, and TWC
Repair Verification Drive Mode. (See
DRIVE MODE [LF].)
• Is the PENDING CODE for this DTC present?
VERIFY AFTER REPAIR PROCEDURE
• Perform the "After Repair Procedure".
10
(See AFTER REPAIR PROCEDURE
• Are any DTC present?
DTC P0038
DETECTION
CONDITION
Downloaded from
OBD
[LF].)

DTC P0038 [LF]

Rear HO2S heater circuit high input
• The PCM monitors the rear HO2S heater control signal at PCM terminal
2C. If the PCM turns the rear HO2S heater on but the rear HO2S heater
circuit has high voltage, the PCM determines that the rear HO2S heater
circuit has malfunction.
Diagnostic support note
• This is a continuous monitor (HO2S heater).
• The MIL illuminates if the PCM detects the above malfunction condition in
two consecutive drive cycles or in one drive cycle while the DTC for the
same malfunction has been stored in the PCM.
• PENDING CODE is available if the PCM detects the above malfunction
condition during first drive cycle.
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Yes Go to the next step.
Repair or replace the wiring harness for
No
open circuit, then go to Step 9.
Replace the PCM, then go to the next
step.
Yes
(See PCM REMOVAL/INSTALLATION
[LF].)
No Go to the next step.
Go to the applicable DTC troubleshooting.
Yes
(See DTC TABLE [LF].)
No Troubleshooting completed.
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B3E010201084W04